Firearm barrel having at least one barrel gas port and method of manufacturing the same

Abstract

Various embodiments are directed to a barrel for a firearm. In various embodiments, a barrel comprises an inner surface defining a bore configured to guide a projectile as the projectile is propelled through the bore by pressurized gas; and a barrel gas port having a gas port depth extending between a port entrance defined by the inner surface of the barrel and a port exit, wherein the barrel gas port is configured to fluidically communicate with the bore and an action of the firearm; wherein the port entrance defines a length dimension defined parallel to a longitudinal axis of the barrel and a width dimension defined perpendicular to the length dimension; and wherein the length dimension of the port entrance is greater than the width dimension of the port entrance. Various embodiments are directed to a firearm comprising the exemplary barrel.

That which is claimed: 
     
       1. A barrel for a rifle configured to fire a bullet from a cartridge, comprising:
 an inner surface comprising rifling, the inner surface defining a bore configured to guide the bullet as the bullet is propelled through the bore by pressurized gas; and 
 a barrel gas port having a gas port depth extending between a port entrance defined by the inner surface of the barrel and a port exit, wherein the barrel gas port is configured to fluidically communicate with the bore and an action of the rifle; 
 wherein the port entrance defines a length dimension defined parallel to a longitudinal axis of the barrel and a width dimension defined perpendicular to the length dimension; 
 wherein the length dimension of the port entrance is greater than the width dimension of the port entrance; and 
 wherein a center point of the length dimension of the port entrance is located closer to a muzzle end of the barrel than a center point of a second length dimension of the barrel gas port defined between the port entrance and the port exit, the port entrance being symmetrical about the center point along the length dimension. 
 
     
     
       2. The barrel of  claim 1 , wherein the length dimension of the port entrance is greater than the second length dimension of the barrel gas port defined parallel to the longitudinal axis between the port entrance and the port exit. 
     
     
       3. The barrel of  claim 2 , wherein the barrel gas port comprises a transition region having a transition region length defined at the port entrance such that the length dimension of the port entrance is defined in part by the transition region length, wherein the transition region length is two times to three times greater than the second length dimension. 
     
     
       4. The barrel of  claim 2 , wherein the length dimension is between 0.5 times and 3.0 times greater than the second length dimension. 
     
     
       5. The barrel of  claim 3 , wherein the width dimension of the port entrance is equal to a second width dimension of the barrel gas port defined at a location of the second length dimension. 
     
     
       6. The barrel of  claim 3 , wherein the width dimension of the port entrance is greater than a second width dimension of the barrel gas port defined at a location of the second length dimension. 
     
     
       7. The barrel of  claim 1 , wherein the barrel gas port defines a flow region defining a constant cross-sectional area for at least a portion of a length of the barrel gas port and a transition region between the port entrance and the flow region. 
     
     
       8. The barrel of  claim 7 , wherein the transition region comprises a larger surface area within the barrel gas port on a muzzle side of the barrel gas port than on an action side of the barrel gas port. 
     
     
       9. The barrel of  claim 7 , wherein the transition region defines a surface angle at a location between the port entrance and the flow region, and wherein the surface angle is between an angle of the bore and an angle of a wall surface of the barrel gas port in the flow region. 
     
     
       10. The barrel of  claim 7 , wherein a transition region muzzle-side wall surface of the transition region comprises a complex curvature defined by a first radius of curvature defined in a first plane and a second radius of curvature defined in a second plane. 
     
     
       11. The barrel of  claim 7 , wherein a transition region action-side surface comprises a partially cylindrical shape corresponding to a shape of a flow region action-side surface adjacent thereto at a first port depth, and wherein a transition region muzzle-side surface transitions to a partially cylindrical shape corresponding to a shape of a flow region muzzle-side surface adjacent thereto at a second port depth, wherein the first port depth and the second port depth are measured from the port entrance, wherein the second port depth is greater than the first port depth, and wherein the barrel gas port defines a cylindrical shape at the second port depth. 
     
     
       12. The barrel of  claim 1 , wherein the barrel gas port extends through the barrel between the port entrance defined in the bore and the port exit defined by an outer surface of the barrel. 
     
     
       13. The barrel of  claim 1 , wherein the barrel comprises a plurality of barrel gas ports, including the barrel gas port, in fluid communication with the bore. 
     
     
       14. The barrel of  claim 13 , wherein each of the plurality of barrel gas ports comprises a respective port entrance defined by the inner surface, wherein each of the respective port entrances defines a respective length dimension and a respective width dimension, wherein the respective length dimension of each of the respective port entrances is greater than the respective width dimension of each respective port entrance. 
     
     
       15. The barrel of  claim 14 , wherein each of the plurality of barrel gas ports is defined at a same axial location along a length of the barrel. 
     
     
       16. The barrel of  claim 1 , wherein the rifling defines one or more rifling elements along the inner surface. 
     
     
       17. The barrel of  claim 16 , wherein the one or more rifling elements comprises a rifling land and a rifling groove defined along the inner surface of the barrel, and wherein the port entrance of the barrel gas port is defined on one of the rifling land, the rifling groove, and partially on both the rifling land and the rifling groove. 
     
     
       18. The barrel of  claim 1 , wherein the gas port depth is defined in a direction at least substantially perpendicular to a bore length of the bore such that the barrel gas port is at least substantially perpendicular to the bore of the barrel. 
     
     
       19. A rifle, comprising the barrel of  claim 1 . 
     
     
       20. The rifle of  claim 19 , further comprising an action and a gas block engaged with the barrel at a location of the port exit of the barrel gas port, wherein the gas port is configured to fluidically connect the action of the firearm-rifle with the bore via the barrel gas port. 
     
     
       21. The rifle of  claim 20 , wherein the rifle is an AR-15 platform rifle. 
     
     
       22. The barrel of  claim 1 , wherein an action-side wall surface edge of the barrel gas port defines an at least substantially uniform cylindrical configuration between a first action-side edge of the port entrance and a second action-side edge of the port exit. 
     
     
       23. A method of manufacturing a barrel for a firearm-rifle configured to fire a bullet from a cartridge, the method comprising:
 providing a barrel for a rifle, the barrel comprising:
 an inner surface comprising rifling, the inner surface defining a bore configured to guide a bullet as the bullet is propelled through the bore by pressurized gas; and 
 a barrel gas port having a gas port depth extending between a port entrance defined by the inner surface of the barrel and a port exit, wherein the barrel gas port is configured to fluidically communicate with the bore and an action of the firearm; 
 wherein the port entrance defines a length dimension defined parallel to a longitudinal axis of the barrel and a width dimension defined perpendicular to the length dimension; and 
 
 machining the barrel to remove an amount of material along at least a portion of the port entrance from a muzzle-side edge of the port entrance such that the length dimension of the port entrance is greater than the width dimension of the port entrance.